To make the onions, in a stainless steel saute pan melt the stick of butter medium heat. Add the onions, garlic, bay leaves, salt and pepper and cook until the onions are soft and caramelized, about 20 - 25 minutes. Add the wine, bring to a boil, reduce the heat and simmer until the wine has evaporated and the onions are dry, about 5 minutes. Discard the bay leaves and set the onions aside to cool.

To make the patties, combine the beef, wine, and onions in a large bowl and mix together well while handling the meat as little as possible; this prevents it from becoming too dense. Divide the mixture into 6 equal portions and form round patties. Sprinkle each patty with salt and pepper, be sure to get both sides. Place the patties in a 13x 9 pan, cover with plastic and refrigerate.

30 minutes prior to cooking, combine the beef stock and demi glaze in whisk to combine. Pour this mixture into the pan with the patties and refrigerate. Turn the patties in the beef mixture after 15 minutes.

Heat the grill to medium-high. When the grill is ready, brush burgers with beef mixture. Place the patties on the grill and cook until done to preference, 4 to 6 minutes per side. Do not push down on the patty because this will release the juices and dry out the burger. Brush burgers with beef mixture again before flipping. The burgers should be cooked through, then turn off the heat and place the cheese atop the patties lowering the grill cover and leave for 2 minutes to melt the cheese. Remove the burgers from the grill.

To assemble the burgers, top 6 ciabatta roll bottoms with a patty each. Cover each with top half of ciabatta roll and slice on a diagonal before serving.